Filter arrangement; sealing system; and methods

ABSTRACT

A filter pack includes a filter construction and a sealing system for sealing the construction within a duct or housing. The filter construction has first and second opposite flow faces and is configured for a straight-through flow. The sealing system includes a frame construction and a compressible seal member. The compressible seal member is molded around a portion of the frame construction. The compressible seal member is sufficiently compressible to form a radial seal between and against the frame construction and a surface of a housing when the filter pack is inserted within the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/218,068,file Aug. 25, 2011, which issued as a U.S. Pat. No. 8,246,708 on Aug.21, 2012. Application Ser. No. 13/218/068 is a continuation ofapplication Ser. No. 11/999,246, filed Dec. 3, 2007, which issued asU.S. Pat. No. 8,034,144 on Oct. 11, 2011. Application Ser. No.11/999/246 is a continuation of application Ser. No. 10/914,510, filedAug. 9, 2004, which issued as U.S. Pat. No. 7,303,604 on Dec. 4, 2007.Application Ser. No. 10/914,510 is a continuation of application Ser.No. 10/424,217, filed Apr. 25, 2003, which issued as U.S. Pat. No.6,350,291 on Feb. 26, 2002. Application Ser. No. 09/502,346 is acontinuation-in-part of application Ser. No. 09/258,481, filed Feb. 26,1999, which issued as U.S. Pat. No. 6,190,432 on Feb. 20, 2001. Thedisclosures of application Ser. Nos. 09/258,481, 09/502,346, 10/055,062,10/424,217, 10/914,510, 11/999,246, and 13/218,068 are incorporatedherein by reference.

FIELD OF THE INVENTION

This disclosure concerns filter constructions for engines and methods offiltering and filter preparation. In particular, the disclosuredescribes a filter arrangement having a sealing system.

BACKGROUND OF THE INVENTION

Gas streams often carry particulate material therein. In many instances,it is desirable to remove some or all of the particulate material from agas flow stream. For example, air intake streams to engines formotorized vehicles or power generation equipment, gas streams directedto gas turbines, and air streams to various combustion furnaces, ofteninclude particulate material therein. The particulate material, shouldit reach the internal workings of the various mechanisms involved, cancause substantial damage thereto. It is therefore preferred, for suchsystems, to remove the particulate material from the gas flow upstreamof the engine, turbine, furnace or other equipment involved. A varietyof air filter or gas filter arrangements have been developed forparticulate removal. In general, however, continued improvements aresought.

SUMMARY OF THE DISCLOSURE

This disclosure describes an engine air flow system. The air flow systemcomprises a filter element construction including a media pack and asealing system. In preferred configurations, the sealing system willhave a frame arrangement and a seal member, where the frame arrangementincludes an extension projecting axially from one of the flow faces ofthe media pack. In particularly preferred arrangements, the seal memberis supported by the extension of the frame arrangement.

Filter element constructions are described herein. Preferred filterelement constructions will include ones such as those characterizedabove.

Methods of filtering systems, servicing filtration systems, andconstructing filter arrangements are described herein. Preferred methodswill use filter elements and constructions as characterized above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, perspective view of one embodiment a filter pack,according to certain principles of this disclosure;

FIG. 2 is a schematic, perspective view of a portion of filter mediausable in the arrangements of FIG. 1;

FIG. 3 is a schematic, perspective view of one approach to manufacturinga filter pack usable in the arrangements of FIG. 1;

FIG. 4 is a schematic, plan view of one embodiment a sealing system ofthe filter pack of FIG. 1;

FIG. 5 is a schematic, fragmented, cross-sectional view of thearrangement of FIG. 1, depicted sealed in an air cleaner for use;

FIG. 6 is a schematic, cross-sectional view of the frame of the sealingsystem of FIG. 4, taken along the line 6-6 of FIG. 4;

FIG. 7 is an enlarged fragmented schematic cross-sectional view of oneembodiment the compressible seal member of the sealing system of FIG. 4,according to principles of this disclosure;

FIG. 8 is a schematic, perspective view of one embodiment of an aircleaner, in which a filter pack according to principles of thisdisclosure can be used;

FIG. 9 is a schematic, cross-sectional view of the air cleaner depictedin FIG. 8, showing the filter pack depicted in FIG. 1 installedtherewithin;

FIG. 10 is a schematic, perspective view of a first alternativeembodiment of a filter pack, according to certain principles of thisdisclosure;

FIG. 11 is a schematic, perspective view of a filter media portion ofthe filter pack of FIG. 10;

FIG. 12 is a schematic, perspective view of one embodiment of a frameportion for a sealing system of the filter pack depicted in FIG. 10;

FIG. 13 is a schematic, cross-sectional view of one embodiment of thesealing system usable in the filter pack depicted in FIG. 10, takenalong the line 13-13 of FIG. 10;

FIG. 14 is a schematic, side elevational view of an alternate embodimentof an air cleaner, according to principles of this disclosure;

FIG. 15 is a schematic, cross-sectional view of the air cleaner depictedin FIG. 14 and taken along the line 15-15 and showing the filter pack ofFIG. 10 installed within;

FIG. 16 is a schematic view of one embodiment of a system in which aircleaners according to the present disclosure are used;

FIG. 17 is an end elevational view of an alternative embodiment of thefilter pack depicted in FIG. 1; and

FIG. 18 is an end elevational view of another embodiment of the filterpack depicted in FIG. 1.

DETAILED DESCRIPTION A. FIGS. 1-7

Attention is directed to FIG. 1. FIG. 1 is a perspective view of a firstembodiment of a filter pack 50. The preferred filter pack 50 depictedincludes filter media 55 and a sealing system 60. In preferredconstructions, the filter media 55 is designed to remove particulatesfrom a fluid, such as air, passing through the filter media 55, whilethe sealing system 60 is designed to seal the filter pack 50 against asidewall of a housing or duct, as shown in FIGS. 8 and 9. By the term“seal,” it is meant that the sealing system 60, under normal conditions,prevents unintended levels of fluid from passing through a regionbetween the filter pack 50 and the sidewall of the housing or duct;i.e., the sealing system 60 inhibits fluid flow from avoiding passagethrough the filtering media 55 of filter pack 50.

In certain preferred arrangements, the filter media 55 will beconfigured for straight-through flow. By “straight-through flow,” it ismeant that the filter media 55 is configured in a construction 100 witha first flow face 105 (corresponding to an inlet end, in the illustratedembodiment) and an opposite, second flow face 110 (corresponding to anoutlet end, in the illustrated embodiment), with fluid flow entering inone direction 114 through the first flow face 105 and exiting in thesame direction 116 from the second flow face 110. When used with aninline-flow housing, in general, the fluid will enter through the inletof the housing in one direction, enter the filter construction 100through the first flow face 105 in the same direction, exit the filterconstruction 100 in the same direction from the second flow face 110,and exit the housing through the housing outlet also in the samedirection.

Although the first flow face 105 is described above as corresponding toan inlet end, and the second flow face 110 is described above ascorresponding to an outlet end, the inlet and outlet ends can bereversed. That is, the first flow face 105 depicted in FIG. 1 cancorrespond to an outlet end, while the second flow face 110 depicted inFIG. 1 can correspond to an inlet end.

In FIG. 1, the first flow face 105 and the second flow face 110 aredepicted as planar and as parallel. In other embodiments, the first flowface 105 and the second flow face 110 can be non-planar, for example,frusto-conical. Further, the first flow face 105 and second flow face110 need not be parallel to each other.

Generally, the filter construction 100 will be a wound construction.That is, the construction 100 will typically include a layer of filtermedia that is turned completely or repeatedly about a center point.Typically, the wound construction will be a coil, in that a layer offilter media will be rolled a series of turns around a center point. Inarrangements where a wound, coiled construction is used, the filterconstruction 100 will be a roll of filter media, typically permeablefluted filter media.

Attention is now directed to FIG. 2. FIG. 2 is schematic, perspectiveview demonstrating the principles of operation of certain preferredmedia usable in the filter constructions herein. In FIG. 2, a flutedconstruction is generally designated at 122. Preferably, the flutedconstruction 122 includes: a layer 123 of corrugations having aplurality of flutes 124 and a face sheet 132. The FIG. 2 embodimentshows two sections of the face sheet 132, at 132A (depicted on top ofthe corrugated layer 123) and at 132B (depicted below the corrugatedlayer 123). Typically, the preferred media construction 125 used inarrangements described herein will include the corrugated layer 123secured to the bottom face sheet 132B. When using this mediaconstruction 125 in a rolled construction, it typically will be woundaround itself, such that the bottom face sheet 132B will cover the topof the corrugated layer 123. The face sheet 132 covering the top of thecorrugated layer is depicted as 132A. It should be understood that theface sheet 132A and 132B are the same sheet 132.

When using this type of media construction 125, the flute chambers 124preferably form alternating peaks 126 and troughs 128. The troughs 128and peaks 126 divide the flutes into an upper row and lower row. In theparticular configuration shown in FIG. 2, the upper flutes form flutechambers 136 closed at the downstream end, while flute chambers 134having their upstream end closed form the lower row of flutes. Thefluted chambers 134 are closed by a first end bead 138 that fills aportion of the upstream end of the flute between the fluting sheet 130and the second facing sheet 132B. Similarly, a second end bead 140closes the downstream end of alternating flutes 136. In some preferredsystems, both the first end bead 138 and second end bead 140 arestraight along all portions of the media construction 125, neverdeviating from a straight path. In some preferred systems, the first endbead 138 is both straight and never deviates from a position at or nearone of the ends of the media construction 125, while the second end bead140 is both straight and never deviates from a position at or near oneof the ends of the media construction 125. The flutes 124 and end beads138, 140 provide the media construction 125 that can be formed intofilter construction 100 and be structurally self-supporting without ahousing.

When using media constructed in the form of media construction 125,during use, unfiltered fluid, such as air, enters the flute chambers 136as indicated by the shaded arrows 144. The flute chambers 136 have theirupstream ends 146 open. The unfiltered fluid flow is not permitted topass through the downstream ends 148 of the flute chambers 136 becausetheir downstream ends 148 are closed by the second end bead 140.Therefore, the fluid is forced to proceed through the fluting sheet 130or face sheets 132. As the unfiltered fluid passes through the flutingsheet 130 or face sheets 132, the fluid is cleaned or filtered. Thecleaned fluid is indicated by the unshaded arrow 150. The fluid thenpasses through the flute chambers 134 (which have their upstream ends151 closed) to flow through the open downstream end 152 (FIG. 1) out thefluted construction 122. With the configuration shown, the unfilteredfluid can flow through the fluted sheet 130, the upper facing sheet132A, or lower facing sheet 132B, and into a flute chamber 134.

Typically, the media construction 125 will be prepared and then wound toform a rolled construction 100 of filter media. When this type of mediais selected for use, the media construction 125 prepared includes thesheet of corrugations 123 secured with the end bead 138 to the bottomface sheet 132B (as shown in FIG. 2, but without the top face sheet132A). In these types of arrangements, the media construction 125 willinclude a leading edge at one end and a trailing edge at the oppositeend, with a top lateral edge and a bottom lateral edge extending betweenthe leading and trailing edges. By the term “leading edge”, it is meantthe edge that will be initially turned or rolled, such that it is at oradjacent to the center or core of the rolled construction. The “trailingedge” will be the edge on the outside of the rolled construction, uponcompletion of the turning or coiling process.

The leading edge and the trailing edge should be sealed between thecorrugated sheet 123 and the bottom face sheet 132B, before winding thesheet into a coil, in these types of media constructions 125. While anumber of ways are possible, in certain methods, the seal at the leadingedge is formed as follows: (a) the corrugated sheet 123 and the bottomface sheet 132B are cut or sliced along a line or path extending fromthe top lateral edge to the bottom lateral edge (or, from the bottomlateral edge to the top lateral edge) along a flute 124 forming a peak126 at the highest point (or apex) of the peak 126; and (b) sealant isapplied between the bottom face sheet 132B and the sheet of corrugations123 along the line or path of cut. The seal at the trailing edge can beformed analogously to the process of forming the seal at the leadingedge. While a number of different types of sealant may be used forforming these seals, one usable material is a non-foamed sealantavailable from H.B. Fuller, St. Paul, Minn., identified under thedesignation HL0842.

When using the media construction 125, it may be desired by the systemdesigner to wind the construction 125 into a rolled construction offilter media, such as the filter construction 100 of FIG. 1. A varietyof ways can be used to coil or roll the media. Attention is directed toFIG. 3. In the particular embodiment shown in FIG. 3, the mediaconstruction 125 is wound about a center mandrel 154 or other element toprovide a mounting member for winding. The center mandrel 154 may beremoved or left to plug to act as a core at the center of thecylindrical filter construction 100 (FIG. 1). It can be appreciated thatnon-round center winding members may be utilized for making otherfiltering media shapes, such as filter media having an oblong, oval,rectangular, or racetrack-shaped profile.

The media construction 125 can also be wound without a mandrel or centercore. One method of forming a coreless rolled construction is asfollows: (a) the troughs 128 of the first few corrugations of thecorrugated sheet 123 spaced from the leading edge are scored from thetop lateral edge to the bottom lateral edge (or from the bottom lateraledge to the top lateral edge) to help in rolling the construction 125;for example, the first four corrugations from the leading edge will havea score line cut along the troughs 128; (b) the bead 140 of sealant isapplied along the top of the sheet of corrugation 123 along the lateraledge opposite from the lateral edge having end bead 138; (c) the leadingedge is initially turned or rolled over against itself and then pinchedtogether to be sealed with the sealant bead 140; and (d) the remainingcorrugated sheet 123 having the bottom face sheet 132B secured theretois coiled or rolled or turned around the pinched leading edge.

In other methods, coreless constructions can be made from the mediaconstruction 125 by automated processes, as described in U.S. Pat. Nos.5,543,007 and 5,435,870, each incorporated by reference herein. In stillother methods, the media construction can be rolled by hand.

When using rolled constructions such as the filter construction 100, thesystem designer will want to ensure that the outside periphery of theconstruction 100 is closed or locked in place to prevent the filterconstruction 100 from unwinding. There are a variety of ways toaccomplish this. In some applications, the outside periphery is wrappedwith a periphery layer. The periphery layer can be a non-porous,adhesive material, such as plastic with an adhesive on one side. Whenthis type of layer is utilized, the periphery layer prevents the filterconstruction 100 from unwinding and prevents the fluid from passingthrough the outside periphery of the filter construction 100,maintaining straight-through flow through the filter construction 100.

In some applications, the filter construction 100 is secured in itsrolled construction by sealing the trailing edge of the mediaconstruction 125 with an adhesive or sealant along a line 160 (FIG. 1)to secure the trailing edge to the outside surface of the filterconstruction 100. For example, a bead of hot-melt may be applied alongthe line 160.

Attention is again directed to FIG. 1. In FIG. 1, the second flow face110 is shown schematically. There is a portion at 112 in which theflutes including the open ends 152 and closed ends 148 are depicted. Itshould be understood that this section 112 is representative of theentire flow face 110. For the sake of clarity and simplicity, the flutesare not depicted in the other remaining portions of the flow face 110.Top and bottom plan views, as well as side elevational views of a filterpack 50 usable in the systems and arrangements described herein aredepicted in copending and commonly assigned U.S. patent application Ser.No. 29/101,193, filed Feb. 26, 1999, and entitled, “Filter ElementHaving Sealing System,” herein incorporated by reference.

Turning now to FIG. 9, the filter construction 100 is shown installed ina housing 305 (which can be part of an air intake duct into an engine orturbo). In the arrangement shown, air flows into the housing 305 at 306,through the filter construction 100, and out of the housing 305 at 307.When media constructions such as filter constructions 100 of the typeshown are used in a duct or housing 305, a sealing system 60 will beneeded to ensure that air flows through the media construction 100,rather than bypass it.

Referring now to FIG. 5, showing an enlarged, fragmented view of thefilter construction 100 installed in the housing 305, the particularsealing system 60 depicted includes a frame construction 170 and a sealmember 250. When this type of sealing system 60 is used, the frameconstruction 170 provides a support structure or backing against whichthe seal member 250 can be compressed against to form a radial seal 172with the duct or housing 305.

Still in reference to FIG. 5, in the particular embodiment shown, theframe construction 170 includes a rigid projection 174 that projects orextends from at least a portion of one of the first and second flowfaces 105, 110 of the filter construction 100. The rigid projection 174,in the particular arrangement shown in FIG. 5, extends axially from thesecond flow face 110 of the filter construction 100. The particular FIG.5 embodiment shows the projection 174 axially projecting above theentire second flow face 110, due to the planar shape of the second flowface 110. In arrangements where the flow face is non-planar, such asfrusto-conical, the projection 174 can be designed to project above onlya portion of the flow face. For example, in a frusto-conical filterconstruction, there could be a center portion at or near the core thatextends above the projection 174.

FIG. 6 depicts a cross-sectional view the particular frame construction170 depicted in FIG. 5. In FIG. 6, the projection 174 shown has a pairof opposite sides 176, 178 joined by an end tip 180. In preferredarrangements, one of the first and second sides 176, 178 will provide asupport or backing to the seal member 250 such that a seal 172 can beformed between and against the selected side 176 or 178 and theappropriate surface of the housing or duct. When this type ofconstruction is used, the projection 174 will be a continuous memberforming a closed loop structure 182 (FIG. 4). The seal member 250 canengage or be adjacent to either an interior side 184 of the loopstructure 182, or the exterior side 186 of the loop structure 182. Whenengaging the interior side 184 of the loop structure 182, the sealmember 250 can be compressed between the projection 174 and a tubularmember inserted within the loop, such that the projection 174 and sealmember 250 circumscribes the tubular member. This would form a radialseal between and against the outer portion of the tubular member and theinterior side 176 of the projection 174 (and the loop structure 182).

The seal member 250 can also engage the exterior portion 186 of the loopstructure 182. When this type of construction is used, a housing or ductmay circumscribe the projection 174 and loop structure 182 including theseal member 250 to form a seal between and against the outer side 178 ofthe projection 174 and an inner surface of the housing or duct.

In certain preferred arrangements, the seal member 250 engages or coversboth of the interior side 184 and exterior side 186 of the loopstructure 182. In the particular embodiment shown in FIG. 5, the sealmember 250 engages the end tip 180 of the projection 174 as well, suchthat the seal member 250 covers the projection 174 from the exteriorside 186, over the end tip 180, and to the interior side 184.

Attention is directed to FIGS. 4, 5 and 6. FIG. 4 is a schematic, planview of the sealing system 60 of FIG. 1; FIG. 5 is a fragmented,schematic, cross-sectional view of the filter pack 50 of FIG. 1installed in housing 305; and FIG. 6 is a schematic, cross-sectionalview of the frame construction 170 of the sealing system 60 of FIG. 4.

In general, when using frame constructions 170 such as those describedherein, the frame construction 170 will include a frame 205. The frame205 may be a variety of shapes. In the particular embodiment illustratedin FIG. 4, the shape of the frame 205 is generally circular. The frame205 depicted in FIG. 4 is convenient in that it is arranged andconfigured for attachment to the second flow face 110 of the filterconstruction 100.

Referring now to FIG. 6, in the particular arrangement depicted, theframe 205 has a band, skirt, or depending lip 251 that is generallycircular and has an inside diameter. Preferably, the inside diameter isapproximately equal to the outside diameter of the filter construction100. The depending lip 251 depends or extends down a first distance froma bottom 252 surface of cross braces 210. The depending lip 251 isarranged and configured to extend radially around the second flow face110 the filter construction 100. Referring now to FIG. 5, in theparticular embodiment depicted, the depending lip 251 extends radiallyaround the second flow face 110 of the filter media 100, such that thedepending lip 251 extends inboard the first distance of the second flowface 110 of the filter construction 100, defining an overlap region 255.

The frame 205 is preferably secured to the filter construction 100. Avariety of ways to secure the frame 205 to the filter construction 100are possible. One particularly preferred way to secure the frame 205 tothe filter construction 100 is by use of an adhesive. In the particularembodiment depicted in FIG. 5, the adhesive is oriented in the overlapregion 255 between the depending lip 251 and the filter construction100.

Preferably, the adhesive permanently affixes the frame 205 to the filterconstruction 100 while preventing the fluid from leaking out through theoverlap region 255 between the filter construction 100 and the frame205. In alternative embodiments, the frame 205 may be temporarilyattached to the filter construction 100. By the term “temporarily,” itis meant that the frame 205 may be removed from the filter construction100 without damaging either the sealing system 60 or the filterconstruction 100.

During use of frames 205 of the type depicted herein, inward forces areexerted around the circumference of the frame 205. Cross braces 210support the frame 205. By the term “support,” it is meant that the crossbraces 210 prevent the frame 205 from radially collapsing under theforces exerted around the circumference of the frame 205.

Referring again to FIG. 6, the particular projection 174 depictedpreferably includes a tip portion 263, or annular sealing support. Inthe one depicted in FIG. 6, the tip portion 263 is generally circularand is arranged and configured for insertion into a housing or duct.When circular, the tip portion 263 defines an inside diameter. Betweenthe tip portion 263 and the depending lip 251, the frame 205 includes astep 253. The step 253 provides a transition area between the largerinside diameter of the depending lip 251 and the smaller inside diameterof the tip portion 263.

When constructed according to the arrangement shown in FIGS. 5 and 6,the tip portion 263 provides support for the compressible seal member250. The compressible seal member 250 is preferably constructed andarranged to be sufficiently compressible to be compressed between thetip portion 263 of the frame 205 and a sidewall 260 of a housing orduct. When sufficiently compressed between the tip portion 263 and thesidewall 260, radial seal 172 is formed between the filter pack 50 andthe sidewall 260.

A variety of ways are possible to secure the seal member 250 to the tipportion 263. One particularly convenient and preferred way is by moldingthe seal member 250 to engage, cover, or overlap both the outer radialside 270 of the tip portion 263 and the inner radial side 271 of the tipportion 263, including the end tip 180 (FIG. 7). One particularembodiment of this configuration is depicted in FIG. 7. The seal member250, in FIG. 7, completely covers the tip portion 263.

The tip portion 263 of the frame 205 defines a wall or support structurebetween and against which a radial seal 172 may be formed by thecompressible seal member 250. The compression of the compressible sealmember 250 at the sealing system 60 is preferably sufficient to form aradial seal under insertion pressures of no greater than 80 lbs.,typically, no greater than 50 lbs., for example, about 20-40 lbs., andlight enough to permit convenient and easy change out by hand.Preferably, the amount of compression of the compressible seal member250 is at least fifteen percent, preferably no greater than fortypercent, and typically between twenty and thirty-three percent. By“amount of compression” it is meant the physical displacement of anoutermost portion of the seal member 250 radially toward the tip portion263 as a percentage of the outermost portion of the seal member 250 in aresting, undisturbed state and not installed within a duct or subject toother forces.

Attention is directed to FIG. 7. FIG. 7 is an enlarged schematic,fragmented view of a particular preferred seal member 250 in anuncompressed state. In the preferred embodiment shown, the seal member250 is a stepped cross-sectional configuration of decreasing outermostdimensions (diameter, when circular) from a first end 264 to a secondend 265, to achieve desirable sealing. Preferred specifications for theprofile of the particular arrangement shown in FIG. 7 are as follows: apolyurethane foam material having a plurality of (preferably at leastthree) progressively larger steps configured to interface with thesidewall 260 (FIG. 5) and provide a fluid-tight seal.

The compressible seal member 250 defines a gradient of increasinginternal diameters of surfaces for interfacing with the sidewall 260.Specifically, in the example shown in FIG. 7, the compressible sealmember 250 defines three steps 266, 267, 268. The cross-sectionaldimension or width of the steps 266, 267, 268 increases the further thestep 266, 267, 268 is from the second end 265 of the compressible sealmember 250. The smaller diameter at the second end 265 allows for easyinsertion into a duct or housing. The larger diameter at the first end264 ensures a tight seal.

In general, for a properly functioning radially sealing structure, thecompressible seal member 250 needs to be compressed when the element ismounted in the housing 305 or duct. In many preferred constructions, itis compressed between about fifteen percent and forty percent (oftenabout twenty to thirty-three percent) of its thickness, in the thickestportion, to provide for a strong robust seal yet still be one that canresult from hand installation of the element with forces on the order of80 pounds or less, preferably 50 pounds or less, and generally 20-40pounds.

In general, the filter pack 50 can be arranged and configured to bepress-fit against the sidewall 260 of the housing 305 or duct. In thespecific embodiment shown in FIG. 5, the compressible seal member 250 iscompressed between the sidewall 260 and the tip portion 263 of the frame205. After compression, the compressible seal member 250 exerts a forceagainst the sidewall 260 as the compressible seal member 250 tries toexpand outwardly to its natural state, forming radial seal 172 betweenand against the tip portion 263 and the sidewall 260.

B. FIGS. 8 and 9

Attention is directed to FIG. 8. FIG. 8 is a schematic, perspective viewof an air cleaner 300. In certain systems, the filter pack 50 isdesigned to be inserted into a housing 305 of an air cleaner 300. Thehousing 305 is typically part of ductwork in airflow communication withan air intake system for an engine. As used herein, the term “ductwork”or “duct” will include structures such as pipes, tubes, and air cleanerhousings.

A variety of housings are usable with the filter pack 50. In theparticular embodiment depicted in FIG. 8, the housing 305 includes abody member or a first housing compartment 310 and a removable cover orsecond housing compartment 315. In some arrangements, the first housingcompartment 310 is affixed to an object, such as a truck. The secondhousing compartment 315 is removably secured to the first housingcompartment 310 by a latching device 320. Preferably, the latchingdevice 320 includes a plurality of latches 325.

While the housing may have a variety of cross-sectional configurations,in the particular embodiment illustrated, the first and second housingcompartments 310, 315 are circular. In the arrangement depicted, thefirst housing compartment 310 has an outlet region 330. The outletregion 330 is designed to allow the fluid to flow out of the filterassembly 300 during use. Similarly, the second housing compartment 315has an inlet region 335. The inlet region 335 is designed to allow thefluid to flow into the filter assembly 300 during use. In preferredconstructions, the housing 305 will be an in-line housing. As such, theoutlet region 330 and inlet region 335 are coaxially aligned, to permitair to flow through the inlet region 335 and flow through the outletregion 330 in the same direction. This can be seen in FIG. 9.

The filter pack 50 is preferably constructed and arranged to bepress-fit against the sidewall 260 of the housing 305. In theillustrated embodiment in FIG. 9, the second end 110 of the filter pack50 with the attached frame 205 and compressible seal member 250 isinserted into the first housing compartment 310. The filter pack 50 ispress-fit into the first housing compartment 310 such that thecompressible seal member 250 is compressed between and against the tipportion 263 of the frame 205 and the sidewall 260 of the first housingcompartment 310, to form radial seal 172 therebetween.

During use of the arrangement depicted in FIG. 9, the fluid enters thehousing assembly 300 at the inlet region 335 of the second housingcompartment 315, in the direction shown at 306. The fluid passes throughthe filter construction 100. As the fluid passes through the filterconstruction 100, contaminants are removed from the fluid. The fluidexits the housing assembly 300 at the outlet region 330, in thedirection of 307. The compressible seal member 250 of the sealing system60 forms radial seal 172 to prevent contaminated fluid from exiting thehousing assembly 300, without first passing through the filterconstruction 100.

C. FIGS. 17 and 18

It should be appreciated that the filter pack 50 can have additionalseparators for ensuring that the appropriate degree of filtering isconducted. The separators can be either upstream of the filter pack 50or downstream of the filter pack 50, depending upon the particularapplication and the desired results. These separators can take the formof pre-cleaners in some embodiments, or post-cleaners (such as safetyfilters or secondary filters). In addition, these separators may be inthe form of single or multiple layers of filtering media, located eitherupstream or downstream of the filter construction 100. The filter mediaused in these applications will typically be selected based upon thedegree of filtering desired and the amount of restriction introduced bythe filter media. For example, it may be that in certain applications,it is desired to filter out large particles (that is, debris such asleaves, butterflies, clumps of dirt) while introducing little moreadditional restriction. In this application, a layer of media such as asieve or screen can be used upstream of the filter construction 100. Itmay also be desired to introduce an additional amount of filtering justdownstream of the filter construction 100. This can be accomplished by alayer (or multiple layers) of media immediately downstream of the filterconstruction 100.

Attention is directed to FIG. 17. FIG. 17 illustrates an alternativeembodiment of the filter pack 50, shown generally at 50′. The filterpack 50′ is configured and constructed analogously as the filter pack50, illustrated in FIG. 1, with the exception of the first flow face105′, that corresponds to an upstream or an inlet end 106′. FIG. 17illustrates an end elevational view of the filter pack 50′, viewing theupstream end 106′. In the particular filter pack 50′ illustrated in FIG.17, the entire upstream end 106′ is covered by a layer of media 107′ forseparating large particles from the gas stream before the gas streamreaches the filter construction 100. Depending upon the application andthe desired degree of filtration and restriction, the media 107′ can beof a variety of types. In many typical applications, the media 107′ willbe sized to allow for the removal of particles such as butterflies,leaves, large clumps of dirt, and other types of debris. One type ofmedia usable has the following characteristics and properties: polyestermaterial; 50% of the fibers being about 15 denier and 50% of the fibersbeing about 6 denier by weight; the binder holding the fibers togetherbeing oil resistant rubber modified PVC; a basis weight of 6.6 oz/yd²(224 g/m²); a thickness of about 0.37 inches; a permeability of about3500 ft/m in a 0.5 in. H₂O restriction.

As described above, it may also be desirable to introduce separationdownstream of the filter construction 100. One example is illustrated inFIG. 18. FIG. 18 is an end elevational view of an alternative embodimentof the filter pack 55, as viewed from the second flow face 110″. Thefilter pack 50″ shown in FIG. 18 is constructed analogously as thefilter pack 50 of FIG. 1, with the exception of an additional separator111″ located downstream of the filter construction 100. While a varietyof embodiments are contemplated, in the particular embodimentillustrated in FIG. 18, the separator 111″ is in the form of a layer ofmedia 112″ located downstream of the filter construction 100. The layerof media 112″ can be either immediately adjacent and against the filterconstruction 100, or it may be located downstream of the frame 205″. Inthe one illustrated in FIG. 18, the media 112″ is immediately downstreamof and against the filter construction 100. That is, the media 112″ islocated between the filter construction 100 and the cross braces 210″ ofthe frame 205″.

The type of media 112″ utilized will depend upon the desired degree offiltering and the amount of restriction that is introduced. The media112″ can be a single layer or multiple layers. In the one illustrated inFIG. 18, the media 112″ includes nonwoven, nonpleated, fibrous depthmedia 113″. One usable material for depth media 113″ has the followingcharacteristics: 1 layer of 4.0-4.8 oz/yd² (136-163 g/m²) polyesterfiber depth media (mixed fibers); 0.55-0.70″ (14-18 mm) thicknessfreestate (as measured under 0.002 psi compression); average fiberdiameter about 21.0 micron (mass weighted average) or about 16.3 micron(length weighted average); permeability (minimum) 500 ft/min (152m/min.); free state solidity about 0.6-1.0%, typically about 0.7%.

It is contemplated that in certain applications, it will be desired tohave a filter pack 50 that includes both an upstream filter 107′ and adownstream filter 111″.

D. FIGS. 10-15

Attention is directed to FIG. 10. FIG. 10 is a perspective view ofanother embodiment of a filter pack 450. In the construction depicted,the filter pack 450 includes filter media 455 and a sealing system 460.The filter media 455 is designed to remove contaminants from a fluid,such as air, passing through the filter media 455. The sealing system460 is designed to seal the filter media 455 to a housing or duct.

In certain preferred arrangements, the filter media 455 will beconfigured in a filter construction 470 with a first flow face 471 andan opposite, second flow face 472. Attention is directed to FIG. 11. Inthe particular embodiment illustrated in FIG. 11, the filterconstruction 470 is configured for straight-through flow. This means, asexplained above, that fluid to be filtered will enter the first flowface 471 in a certain direction 477 (FIG. 10) and exit the second flowface 472 in the same direction 478 (FIG. 10).

The filter construction 470 can have a variety of configurations andcross-sectional shapes. In the particular embodiment illustrated in FIG.11, the filter construction 470 has a non-circular cross-section. Inparticular, the FIG. 11 embodiment of the filter construction 470 has anob-round or “racetrack” cross-sectional shape. By “racetrack”cross-sectional shape, it is meant that the filter construction 470includes first and second semicircular ends 511, 512 joined by a pair ofstraight segments 513, 514.

In general, the filter construction 470 will be a wound construction.That is, the construction 470 will include a layer of filter media thatis turned completely or repeatedly about a centerpoint. In certainpreferred arrangements, the wound construction will be a coil, in that alayer of filter media will be rolled a series of turns about acenterpoint. In further preferred arrangements, the filter construction470 will be a rolled construction, typically a roll of filter media, forexample permeable fluted filter media.

Many different ways of manufacturing the media construction 470 can beused. In some techniques, a single-faced filter media, such as thefilter media 122 illustrated in FIG. 2, is wound about a center mandrelor other structure to provide a mounting member for winding. The centermandrel may be removed or left to plug the center of the filterconstruction 470. In the particular embodiment shown in FIG. 11, acenter core 454 is illustrated as occupying the center of the coil offilter media 455.

In FIGS. 10 and 11, certain portions 475 are depicted showing theflutes, including the open and closed ends. It should be understood thatthis portion or section 475 is representative of the entire flow face472 (as well as the first flow face 471). For the sake of clarity andsimplicity, the flutes are not depicted in the other remaining portionsof the flow face 472. Top and bottom plan views, as well as sideelevational views of the filter pack 450 usable in the systems andarrangements described herein are depicted in copending and commonlyassigned U.S. patent application Ser. No. 29/101,193, filed Feb. 26,1999, and entitled, “Filter Element Having Sealing System,” herein andincorporated by reference.

As with the embodiment of FIG. 1, the filter pack 450 includes a sealingsystem 460. In preferred constructions, the sealing system 460 includesa frame 605 and a seal member 650.

While a variety of configurations are contemplated herein, oneparticularly preferred embodiment of the frame 605 is shown inperspective view in FIG. 12.

In the particular arrangement depicted in FIG. 12, the frame 605 has anon-circular, for example, obround and in particular, a racetrack shapeand is arranged and configured for attachment to the second end 510 ofthe filter media 455. In particular, the frame 605 has a band or skirtor depending lip 651 that is generally racetrack shaped. The dependinglip 651 depends or extends down a distance from a bottom surface 652 ofcross braces 610. The depending lip 651 is arranged and configured toextend radially around the second end 570 of filter construction 470.Referring now to FIG. 10, in the embodiment depicted, the depending lip651 of the frame 605 extends radially around the second end 510 of thefilter construction 470, such that the depending lip 651 extends inboardthe distance from bottom surface 652 of cross braces 610 of the secondend 510 of the filter construction 470, defining an overlap region 555(FIG. 15).

The frame 605 can be secured to the filter construction 470 in a numberof ways. One particularly convenient way is by securing the frame 605 tothe filter construction 470 by adhesive. In the specific embodimentillustrated and FIG. 15, the adhesive is placed in the overlap region555 between the frame 605 and the filter construction 470 as previouslydescribed herein.

During use of the arrangements depicted, inward forces are exertedaround the circumference of the frame 605. Inward forces exerted againstthe semicircular ends 511, 512 can cause the straight segments 513, 514to bow or bend. Structure is provided as part of the frame 605 toprevent the straight segments 513, 514 from bowing. While a variety ofstructures are contemplated herein, in the particular embodimentillustrated in FIG. 12, cross braces 610 are provided to providestructural rigidity and support to the straight segments 513, 514. Ascan be seen in FIG. 12, the particular cross braces 610 depicted form atruss system 612 between the opposing straight segments 513, 514. Thetruss system 612 includes a plurality of rigid struts 614, preferablymolded as a single piece with the remaining portions of the frame 605.

In certain preferred constructions, the frame 605 is constructedanalogously to the frame 205. As such, and in reference now to FIGS. 12and 13, the frame 605 includes a tip portion 663. In preferredarrangements, the tip portion 663 acts as an annular sealing support. Inthe construction depicted, the tip portion 663 has the samecross-sectional configuration as the filter construction 470. In theparticular embodiment illustrated in FIG. 12, the tip portion isnoncircular, specifically, racetrack shaped. In preferredimplementations, and in reference to the particular embodiment shown inFIG. 13, between the tip portions 663 and the depending lip 651, theframe 605 includes a step 653. The step 653 provides a transition areabetween the cross-sectional width of the depending lip 651 and thesmaller cross-sectional width of the tip portion 663.

In preferred systems, the compressible seal member 650 has structureanalogous to the that of the compressible seal member 250 of FIG. 7.

Preferably, the filter pack 450 will be installed in a duct or an aircleaner housing. In certain preferred applications, the air cleanerhousing will be an in-line housing. FIG. 14 illustrates an air cleaner670 having one type of in-line housing 672. In FIG. 14, the housingdepicted is a two-piece housing including a cover 674 and a body member676. The cover 674 defines an airflow inlet 678. The body member 676defines an airflow outlet 680. The housing further includes apre-cleaner arrangement 679 upstream of the filter pack 450, such asthat described in U.S. Pat. Nos. 2,887,177 and 4,162,906, incorporatedby reference herein. In the one depicted, the pre-cleaner arrangement679 is in the cover 674. The cover 674 includes a dust ejector 681 thatexpels dust and debris collected in the pre-cleaner 679.

FIG. 15 is a schematic cross-sectional view of the air cleaner 670 ofFIG. 14 and showing the filter pack 450 installed therewithin.

The compressible seal member 650 is compressed between the sidewall 660and the tip portion 663 of the frame 605. As the filter pack 450 ispress-fit, the compressible seal member 650 is compressed between andagainst the frame 605 (specifically, in the particular embodiment shown,the tip portion 663) and the sidewall 660. After compression, thecompressible seal member 650 exerts a force against the sidewall 660 asthe compressible seal member 650 tries to expand outwardly to itsnatural state, forming a radial seal 685 with the sidewall 660.

E. Systems and Methods of Operation

The filter constructions and arrangements described herein are usable ina variety of systems. One particular type of system is depictedschematically in FIG. 16 generally at 700. In FIG. 16, equipment 702,such as a vehicle, having an engine 703 with some defined rated air flowdemand, for example at least 500 cfm, and typically 700-1200 cfm isshown schematically. The equipment 702 may comprise a bus, anover-the-highway truck, an off-road vehicle, a tractor, or marineapplication such as a powerboat. The engine 703 powers the equipment702, through use of an air and fuel mixture. In FIG. 16, air flow isshown drawn into the engine 703 at an intake region 705. An optionalturbo 706 is shown in phantom, as optionally boosting the air intakeinto the engine 703. An air cleaner 710 having a filter construction 712and a secondary element 713 is upstream of the engine 703 and the turbo706. In general, in operation, air is drawn in at arrow 714 into the aircleaner 710 and through a primary element 712 and secondary element 713.There, particles and contaminants are removed from the air. The cleanedair flows downstream at arrow 716 into the intake 705. From there, theair flows into the engine 703 to power the equipment 702.

F. Change Out and Replacement

In certain preferred applications, the filter packs described herein areremovable and replaceable from whatever system in which they areinstalled. For example, the filter pack 50, or filter pack 650, will beinstalled in an air cleaner housing such as those shown in FIGS. 9 and15, respectively. After a certain number of hours of use, the media inthe filter constructions will become occluded, and the restriction inthe filter packs will increase. In preferred applications, the filterpacks will be periodically replaced to maintain the appropriate removalof particulates from a fluid, without introducing too high of arestriction.

In some applications, the filter constructions herein will include avisual indicator of useful life. Some systems may include a restrictionindicator to provide information to the user regarding the appropriatetime to change out the filter pack.

To service the air cleaner arrangements described herein, the user willneed access the filter pack. For example, if the filter pack isinstalled in an air cleaner housing such as those shown in FIG. 9 orFIG. 15, the user will unlatch the cover from the body member, andremove the cover from the body member. This will expose an opening. Theuser will grasp the filter pack and break the radial seal formed by thefilter pack against the sidewall of the housing or duct. In certainsystems, the seal member and the housing or duct will be designed suchthat the user will need to exert a force of no more than about 80 lbs.,preferably no more than 50 lbs., and in some applications between 15 and40 lbs. to break the radial seal and remove the filter pack. The userwill then pull the filter pack through the opening formed by the bodymember. The old filter pack may then be disposed of. In certainpreferred systems, the filter pack will be constructed of non-metallicmaterials, such that it is readily incineratable. For example, in somepreferred constructions, the filter pack will comprise at least 95percent, and typically at least 98 percent nonmetallic materials.

To install a new filter pack, the user grasps the filter pack andinserts it through an opening in the duct or housing. The filter pack isinserted into the opening until the seal member is sufficientlycompressed against the inner annular wall of the housing to form aradial seal between and against the housing wall and the tip portion ofthe frame. The cover may then be oriented over the exposed end of thefilter pack to close the opening. The cover may then be latched to thebody member.

G. Example Construction

In this section, examples are provided of a set of operatingspecifications. These are intended as an example. A wide variety ofalternate sizes can be used.

1. FIGS. 1-8.

The axial length of the filter media 100 of FIG. 2 will be between 3inches (about 8 cm) and 10 inches (about 25 cm), and in one examplewould be approximately 6 inches (about 15 cm). The outside diameter ofthe filter media 100 will be between 3 inches (about 38 cm) and 15inches (about 38 cm), and in one example would be approximately 10inches (about 25 cm).

The distance (FIG. 5) that the depending lip 251 of the frame 205 (FIG.5) extends inboard of the second end 110 (FIG. 5) of the filterconstruction 100 will be between 0.2 inches (about 5 mm) and 1 inch(about 2.5 cm), and in one example would be 0.6 inches (about 1.5 cm).The diameter of the depending lip 251 will be between 3 inches (about 7cm) and 15 inches (about 38 cm), and in one example would beapproximately 10 inches (about 25 cm). The diameter of the tip portion263 will be between 2.5 inches (about 6 cm) and 14 inches (36 cm), andin one example would be approximately 9.5 inches (about 24 cm).

The filter element will provide at least 5 sq. ft and typically 20-130sq. ft., for example about 45 sq. ft. of media surface area. It willoccupy a volume of no greater than about 1 ft³, and typically between0.03-0.5 ft³, and for example about 0.2-0.4 ft³.

2. FIG. 9

The diameter of the outlet region 330 (FIG. 9) of the first housingcompartment 310 (FIG. 9) will be between 3 inches (about 8 cm) and 10inches (about 25 cm), and in one example would be 7 inches (about 18cm). The diameter (FIG. 9) of the inlet region 335 (FIG. 9) of thesecond housing compartment 315 (FIG. 9) will be between 3 inches (about8 cm) and 10 inches (about 25 cm), and in one example would be 5.8inches (about 15 cm).

3. FIGS. 10-14

The axial length of the filter construction 470 will be between 3 inches(about 8 cm) and 10 inches (about 25 cm), and in one example would beapproximately 6 inches (about 15 cm). The semicircular ends 511, 512will have a radius of between 1 inch (about 2.5 cm) and 5 inches (about13 cm), and in one example have a radius of 2.7 inches (about 7 cm). Thestraight segments 513, 514 will have a length greater than 0.1 inches(about 2.5 mm), and in one example, would be 4.9 inches (about 12 cm).

Preferably, the distance that the frame 605 extends inboard of thefilter construction 470 will be between 0.2 inches (about 5 mm) and 1inch (about 2.5 cm), and in one example would be 0.6 inches (about 1.5cm).

The filter element will provide at least 5 sq. ft and typically 20-130sq. ft., for example about 45 sq. ft. of media surface area. It willoccupy a volume of no greater than about 1 ft³, and typically between0.03-0.5 ft³, and for example about 0.2-0.4 ft³.

H. Example Materials

In this section, examples are provided of usable materials. Theparticular choice for any given material will vary, depending on thefiltering application. In other words, the particular material selectedfor the systems usable herein will be decided upon by the systemdesigner based on the system requirements. A variety of materials arepossible. The following section provides examples of materials that havebeen found to be suitable.

The media 122 can comprise cellulose. One example of media usable in thesystem described above is as follows: cellulose media with the followingproperties: a basis weight of about 45-55 lbs./3000 ft² (84.7 g/m²), forexample, 48-54 lbs./3000 ft²; a thickness of about 0.005-0.015 in, forexample about 0.010 in. (0.25 mm); frazier permeability of about 20-25ft/min, for example, about 22 ft/min (6.7 m/min); pore size of about55-65 microns, for example, about 62 microns; wet tensile strength of atleast about 7 lbs/in, for example, 8.5 lbs./in (3.9 kg/in); burststrength wet off of the machine of about 15-25 psi, for example, about23 psi (159 kPa).

The cellulose media can be treated with fine fiber, for example, fibershaving a size (diameter) of 5 microns or less, and in some instances,submicron. A variety of methods can be utilized for application of thefine fiber to the media. Some such approaches are characterized, forexample, in U.S. Pat. No. 5,423,892, column 32, at lines 48-60. Morespecifically, such methods are described in U.S. Pat. Nos. 3,878,014;3,676,242; 3,841,953; and 3,849,241, incorporated herein by reference.An alternative is a trade secret approach comprising a fine polymericfiber web positioned over conventional media, practiced under tradesecret by Donaldson Company under the designation ULTRA-WEB®. Withrespect to the configurations of the filter element and the operation ofthe sealing system, there is no particular preference for: how the finefibers are made; and, what particular method is used to apply the finefibers. Enough fine fiber would be applied until the resulting mediaconstruction would have the following properties: initial efficiency of99.5% average, with no individual test below 90%, tested according toSAE J726C, using SAE fine dust; and an overall efficiency of 99.98%average, according to SAE J726C.

The frame 205 (FIG. 5) will be constructed of a material that willprovide structural integrity and is not subject to creep. The frame 205will be constructed of a non-metallic material such that it isenvironmentally friendly and either recyclable or readily incineratable.The frame 205 can be constructed from most plastics, for example, glassreinforced plastic. One usable reinforced plastic is propylene or nylon.Of course, other suitable materials may be used.

The compressible seal member 250 (FIG. 6) can be made from a variety ofmaterials. There is no particular preference, provided that the sealmember 250 forms a seal in the proper location under compression. Oneusable material will be a soft polymeric material, such as foamedurethane. One example usable material includes foamed polyurethane,processed to an end product having an “as molded” density of fourteen totwenty-two pounds per cubic foot. Foamed polyurethanes are availablefrom a variety of sources, such as BASF Corporation of Wyandotte, Mich.One example of a foamed polyurethane comprises a material made withI35453R resin and I305OU isocyanate, which is sold exclusively to theassignee Donaldson by BASF Corporation.

The materials should be mixed in a mix ratio of 100 parts I35453 resinto 36.2 parts I305OU isocyanate (by weight). The specific gravity of theresin is 1.04 (8.7 pounds/gallon), and for the isocyanate it is 1.20 (10pounds/gallon). The materials are typically mixed with a high dynamicshear mixer. The component temperatures should be seventy to ninety-fivedegrees Fahrenheit. The mold temperatures should be 115-135 degreesFahrenheit.

The resin material I35453R has the following description:

(a) Average molecular weight

-   -   1) Base polyether polyol=500-15,000    -   2) Diols=60-10,000    -   3) Triols=500-15,000

(b) Average functionality

-   -   1) total system=1.5-3.2

(c) Hydroxyl number

-   -   1) total systems=100-300

(d) Catalysts

-   -   1) amine=Air Products 0.1-3.0 PPH    -   2) tin=Witco 0.01-0.5 PPH

(e) Surfactants

-   -   1) total system=0.1-2.0 PPH

(f) Water

-   -   1) total system=0.03-3.0 PPH

(g) Pigments/dyes

-   -   1) total system=1-5% carbon black

(h) Blowing agent

-   -   1) 0.1-6.0% HFC 134A.

The I3050U isocyanate description is as follows:

(a) NCO content—22.4-23.4 wt %

(b) Viscosity, cps at 25° C.=600-800

(c) Density=1.21 g/cm³ at 25° C.

(d) Initial boiling pt.—190° C. at 5 mm Hg

(e) Vapor pressure=0.0002 Hg at 25° C.

(f) Appearance—colorless liquid

(g) Flash point (Densky-Martins closed cup)=200° C.

The above is a complete description of principles of the invention. Manyembodiments can be made according to principles of this disclosure.

We claim:
 1. An air filter pack for filtering air, the air filter packcomprising: (a) an air filter media construction configured forstraight-through flow and having a first flow face and an oppositesecond flow face, the filter media construction being closed to flow ofunfiltered air completely therethrough, and the filter mediaconstruction having a non-circular cross-section; and (b) a frameconstruction including: (a) a portion surrounding the air filter mediaconstruction adjacent one of the flow faces; (b) a rigid projectionsecured to the portion surrounding the air filter media construction;and, (c) a seal member mounted on the rigid projection and including aportion oriented to form a radial seal when the filter pack is installedfor use, wherein no part of the seal member portion that is oriented toform a radial seal is oriented surrounding the filter mediaconstruction.
 2. A filter pack according to claim 1 wherein: (a) therigid projection of the frame construction provides a backing againstwhich the seal member is pressed when the filter pack is installed foruse.
 3. A filter pack according to claim 1 wherein: (a) the seal memberis configured to form an outwardly directed radial seal.
 4. A filterpack according to claim 1 wherein: (a) the seal member is configured toform an inwardly directed radial seal.
 5. A filter pack according toclaim 1 wherein: (a) the frame construction is permanently affixed tothe filter media construction.
 6. A filter pack according to claim 1including: (a) a cross-brace arrangement extending across the frameconstruction.
 7. A filter pack according to claim 6 wherein: (a) thecross-brace arrangement is positioned at a location between: the portionof the seal member oriented to form a radial seal; and, the filter mediaconstruction.
 8. A filter pack according to claim 1 wherein: (a) theframe construction includes a step extending from a location surroundingthe filter media construction to a location over, and in overlap withone of the flow faces of the filter media construction.
 9. A filter packaccording to claim 1 wherein: (a) the filter media constructioncomprises fluted media secured to facing media.
 10. An air filter packfor filtering air; the air filter pack comprising: (a) an air filtermedia construction configured for straight-through flow; the mediaconstruction having a first flow face; and an opposite second flow face;(i) the air filter media construction comprising a coiled construction;(ii) the air filter media construction comprising a layer of flutessecured to a face sheet; and, the air filter media construction beingclosed to flow of unfiltered air completely therethrough; and, (b) anon-porous periphery layer surrounding and enclosing an outsideperiphery of the filter media construction and preventing air frompassing through the outside periphery of the filter media construction;and, (c) a sealing system including a seal member positioned on a frameconstruction; (i) the seal member including a portion oriented to form aradial seal; (A) no part of the seal member portion oriented to form aradial seal being oriented surrounding the filter media.
 11. An airfilter pack according to claim 10 wherein: (a) each one of the first andsecond flow faces is planar.
 12. A filter pack according to claim 10wherein: (a) the frame construction includes a rigid projectionproviding a backing against which the seal member is pressed when thefilter pack is installed for use.
 13. A filter pack according to claim10 wherein: (a) the seal member comprises polyurethane foam.
 14. Afilter pack according to claim 13 wherein: (a) the seal member comprisesfoamed polyurethane having an as molded density within the range of14-22 lbs/cu. ft.
 15. A filter pack according to claim 10 wherein: (a)the frame construction includes a rigid projection having an interiorside, an exterior side and an end tip; and, (b) the seal member extendsover at least one side and the end tip.
 16. A filter pack according toclaim 15 wherein: (a) the seal member extends from the exterior sideover the end tip to the interior side of the rigid projection.
 17. Afilter pack according to claim 15 wherein: (a) the seal member isconfigured to form an outwardly directed radial seal.
 18. A filter packaccording to claim 15 wherein: (a) the seal member is configured to forman inwardly directed radial seal.
 19. A filter pack according to claim10 including: (a) a cross-brace arrangement extending across the frameconstruction.
 20. A filter pack according to claim 19 wherein: (a) thecross-brace arrangement is positioned at a location between: the portionof the seal member oriented to form a radial seal; and, the filter mediaconstruction.
 21. A filter pack according to claim 19 wherein: (a) thecross-brace arrangement is positioned against one of the flow faces. 22.A filter pack according to claim 10 wherein: (a) the filter mediaconstruction has a circular cross-section.
 23. A filter pack accordingto claim 10 wherein: (a) the filter media construction has anon-circular cross-section.
 24. A filter pack according to claim 12wherein: (a) the filter media construction has a cross-section shapewith opposite semi-circular ends.
 25. A filter pack according to claim10 wherein: (a) the seal member defines a circular shaped radial seal.26. A filter pack according to claim 10 wherein: (a) the seal memberdefine a non-circular shaped radial seal.
 27. An air filter pack forfiltering air; the air filter pack comprising: (a) air filter mediaconstruction configured to have a first flow face and an opposite secondflow face; (i) the air filter media construction being closed to flow ofunfiltered air completely therethrough; and, (ii) the filter mediaconstruction comprising fluted media secured to facing media; (b) asealing system including a seal member positioned on a frameconstruction; (i) the seal member including a portion oriented forengagement with a housing portion to form a radial seal; and, (c) across-brace arrangement extending across the frame construction at alocation adjacent one of the flow faces of the air filter mediaconstruction.
 28. A filter pack according to claim 27 wherein: (a) theframe construction includes a rigid projection that provides a backingagainst which the seal member is pressed when the filter pack isinstalled for use.
 29. A filter pack according to claim 28 wherein: (a)the seal member is configured to form an outwardly directed radial seal.30. A filter pack according to claim 28 wherein: (a) the seal member isconfigured to form an inwardly directed radial seal.
 31. A filter packaccording to claim 28 wherein: (a) the filter media construction has acircular cross-section.
 32. A filter pack according to claim 28 wherein:(a) the filter media construction has a non-circular cross-section. 33.An air cleaner assembly comprising: (a) an air filter pack according toclaim 1; and (b) a housing including a body member and a removablecover; (i) the housing including an air flow inlet region and an airflow outlet region; and, (ii) the filter pack being removably mountedwithin an interior of the housing, at a location between the inletregion and the outlet region; (A) the filter pack being removablypositioned with the seal member radially sealed to the housing.
 34. Afilter packet according to claim 1 wherein: (a) the air filter mediaconstruction comprises cellulose media treated with fibers having adiameter of 5 microns or less.
 35. A filter packet according to claim 10wherein: (a) the air filter media construction comprises cellulose mediatreated with fibers having a diameter of 5 microns or less.
 36. A filterpacket according to claim 27 wherein: (a) the air filter mediaconstruction comprises cellulose media treated with fibers having adiameter of 5 microns or less.